def test_adjoint_stack_3D(self):
"""Test the adjoint operator for the 3D non-Cartesian Fourier transform
"""
for channel in self.num_channels:
print("Testing with num_channels=" + str(channel))
for i in range(self.max_iter):
mask = np.random.randint(2, size=(self.N, self.N))
sampling_z = np.random.randint(2, size=self.N)
sampling_z[self.N // 2 - 10:self.N // 2 + 10] = 1
Nz = sampling_z.sum()
mask = convert_mask_to_locations(mask)
z_locations = np.repeat(
convert_mask_to_locations(sampling_z),
mask.shape[0],
)
z_locations = z_locations[:, np.newaxis]
kspace_loc = np.hstack([np.tile(mask, (Nz, 1)), z_locations])
print("Process Stacked3D-FFT test in 3D '{0}'...", i)
fourier_op = Stacked3DNFFT(
kspace_loc=kspace_loc,
shape=(self.N, self.N, self.N),
implementation='cpu',
n_coils=channel,
)
Img = np.random.random((channel, self.N, self.N, self.N)) + \
1j * np.random.random((channel, self.N, self.N, self.N))
f = np.random.random((channel, kspace_loc.shape[0])) + \
1j * np.random.random((channel, kspace_loc.shape[0]))
f_p = fourier_op.op(Img)
I_p = fourier_op.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-10)
print("Stacked FFT in 3D adjoint test passes")
def test_self_calibrating_reconstruction(self):
""" Test all the registered transformations.
"""
self.num_channels = 2
print("Process test for SelfCalibratingReconstructor ::")
for i in range(len(self.test_cases)):
print("Test Case " + str(i) + " " + str(self.test_cases[i]))
image, nb_scale, optimizer, recon_type, name = self.test_cases[i]
image_multichannel = np.repeat(image.data[np.newaxis],
self.num_channels,
axis=0)
if optimizer == 'condatvu':
formulation = "analysis"
else:
formulation = "synthesis"
if recon_type == 'cartesian':
fourier = FFT(samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels)
else:
fourier = NonCartesianFFT(samples=convert_mask_to_locations(
self.mask),
shape=image.shape,
n_coils=self.num_channels)
kspace_data = fourier.op(image_multichannel)
linear_op, regularizer_op = \
self.get_linear_n_regularization_operator(
wavelet_name=name,
dimension=len(fourier.shape),
nb_scale=2,
n_coils=self.num_channels,
gradient_formulation=formulation,
)
# For self calibrating reconstruction the n_coils
# for wavelet operation is 1
linear_op.n_coils = 1
reconstructor = SelfCalibrationReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation=formulation,
verbose=0,
)
x_final, costs, _ = reconstructor.reconstruct(
kspace_data=kspace_data,
optimization_alg=optimizer,
num_iterations=self.num_iter,
)
fourier_0 = FFT(
samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels,
)
recon = fourier_0.adj_op(fourier_0.op(image_multichannel))
np.testing.assert_allclose(np.abs(x_final),
np.sqrt(np.sum(np.abs(recon)**2,
axis=0)),
rtol=1e-3)
def test_sparse_calibrationless_reconstruction(self):
""" Test all the registered transformations.
"""
self.num_channels = 2
print("Process test for SparseCalibrationlessReconstructor ::")
for i in range(len(self.test_cases)):
print("Test Case " + str(i) + " " + str(self.test_cases[i]))
image, nb_scale, optimizer, recon_type, name = self.test_cases[i]
image_multichannel = np.repeat(image.data[np.newaxis],
self.num_channels,
axis=0)
if optimizer == 'condatvu':
formulation = "analysis"
else:
formulation = "synthesis"
if recon_type == 'cartesian':
fourier = FFT(samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels)
else:
fourier = NonCartesianFFT(samples=convert_mask_to_locations(
self.mask),
shape=image.shape,
n_coils=self.num_channels)
kspace_data = fourier.op(image_multichannel)
linear_op, regularizer_op = \
self.get_linear_n_regularization_operator(
wavelet_name=name,
dimension=len(fourier.shape),
nb_scale=2,
n_coils=2,
n_jobs=2,
gradient_formulation=formulation,
)
reconstructor = CalibrationlessReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation=formulation,
verbose=1,
)
x_final, costs, _ = reconstructor.reconstruct(
kspace_data=kspace_data,
optimization_alg=optimizer,
num_iterations=self.num_iter,
)
fourier_0 = FFT(
samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels,
)
data_0 = fourier_0.op(image_multichannel)
# mu is 0 for above single channel reconstruction and
# hence we expect the result to be the inverse fourier transform
np.testing.assert_allclose(x_final, fourier_0.adj_op(data_0))
def test_extract_k_space_center_3D(self):
""" This test ensures that the output of the non cartesian kspace
extraction is same a that of mimicked cartesian extraction in 3D
"""
_mask = np.ones((self.N, self.N, self.Nz))
_samples = convert_mask_to_locations(_mask)
Img = (np.random.randn(self.num_channel, self.N, self.N, self.Nz) +
1j * np.random.randn(self.num_channel, self.N, self.N, self.Nz))
Nby2_percent = self.N * self.percent / 2
Nzby2_percent = self.Nz * self.percent / 2
low = int(self.N / 2 - Nby2_percent)
high = int(self.N / 2 + Nby2_percent + 1)
lowz = int(self.Nz / 2 - Nzby2_percent)
highz = int(self.Nz / 2 + Nzby2_percent + 1)
center_Img = Img[:, low:high, low:high, lowz:highz]
thresh = self.percent * 0.5
data_thresholded, samples_thresholded = \
extract_k_space_center_and_locations(
data_values=np.reshape(Img, (self.num_channel,
self.N * self.N * self.Nz)),
samples_locations=_samples,
thr=(thresh, thresh, thresh),
img_shape=(self.N, self.N, self.Nz))
np.testing.assert_allclose(center_Img.reshape(data_thresholded.shape),
data_thresholded)
def test_NFFT_2D(self):
"""Test the adjoint operator for the 2D non-Cartesian Fourier
transform, with density compensator set to 1, to vet the code
path, the test is unchanged otherwise
"""
for num_channels in self.num_channels:
print("Testing with num_channels=" + str(num_channels))
for i in range(self.max_iter):
_mask = np.random.randint(2, size=(self.N, self.N))
_samples = convert_mask_to_locations(_mask)
print("Process NFFT in 2D test '{0}'...", i)
fourier_op = NonCartesianFFT(samples=_samples,
shape=(self.N, self.N),
n_coils=num_channels,
implementation='cpu',
density_comp=np.ones(
(num_channels,
_samples.shape[0])))
Img = np.random.randn(num_channels, self.N, self.N) + \
1j * np.random.randn(num_channels, self.N, self.N)
f = np.random.randn(num_channels, _samples.shape[0]) + \
1j * np.random.randn(num_channels, _samples.shape[0])
f_p = fourier_op.op(Img)
I_p = fourier_op.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-10)
print(" NFFT in 2D adjoint test passes")
def test_FFT(self):
"""Test the adjoint operator for the 2D non-Cartesian Fourier transform
"""
for i, num_coil in product(range(self.max_iter), self.num_channels):
_mask = np.random.randint(2, size=(self.N, self.N))
_samples = convert_mask_to_locations(_mask)
print("Process FFT test '{0}'...", i)
fourier_op_dir = FFT(samples=_samples,
shape=(self.N, self.N),
n_coils=num_coil)
fourier_op_adj = FFT(samples=_samples,
shape=(self.N, self.N),
n_coils=num_coil)
Img = np.squeeze(
np.random.randn(num_coil, self.N, self.N) +
1j * np.random.randn(num_coil, self.N, self.N))
f = np.squeeze(
np.random.randn(num_coil, self.N, self.N) +
1j * np.random.randn(num_coil, self.N, self.N))
f_p = fourier_op_dir.op(Img)
I_p = fourier_op_adj.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-10)
print(" FFT adjoint test passes")
def test_extract_k_space_center_2D_fft(self):
""" Ensure that the extracted k-space center is right
for cartesian case"""
mask = np.random.randint(0, 2, (self.N, self.N))
samples = convert_mask_to_locations(mask)
Img = (np.random.randn(self.num_channel, self.N, self.N) +
1j * np.random.randn(self.num_channel, self.N, self.N))
Nby2_percent = self.N * self.percent / 2
low = int(self.N / 2 - Nby2_percent)
high = int(self.N / 2 + Nby2_percent + 1)
center_Img = Img[:, low:high, low:high]
cutoff_mask = mask[low:high, low:high]
locations = np.where(cutoff_mask.reshape(cutoff_mask.size))
center_Img = center_Img.reshape(
(center_Img.shape[0], cutoff_mask.size))[:, locations[0]]
thresh = self.percent * 0.5
data_thresholded, samples_thresholded = \
extract_k_space_center_and_locations(
data_values=Img,
samples_locations=samples,
thr=(thresh, thresh),
img_shape=(self.N, self.N))
np.testing.assert_allclose(
center_Img,
data_thresholded)
def test_NUFFT_3D(self):
"""Test the adjoint operator for the 3D non-Cartesian Fourier transform
on GPU
"""
for num_channels in self.num_channels:
for platform in self.platforms:
_mask = np.random.randint(2, size=(self.N, self.N, self.N))
_samples = convert_mask_to_locations(_mask)
fourier_op_dir = NonCartesianFFT(samples=_samples,
shape=(self.N, self.N,
self.N),
implementation=platform,
n_coils=num_channels)
Img = (np.random.randn(num_channels, self.N, self.N, self.N) +
1j * np.random.randn(num_channels, self.N, self.N,
self.N))
f = (np.random.randn(num_channels, _samples.shape[0]) +
1j * np.random.randn(num_channels, _samples.shape[0]))
f_p = fourier_op_dir.op(Img)
I_p = fourier_op_dir.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-5)
print("NFFT in 3D adjoint test passes on GPU with"
"num_channels = " + str(num_channels) + " on "
"platform " + platform)
def test_sensitivity_extraction_2D(self):
""" This test ensures that the output of the non cartesian kspace
extraction is same a that of mimicked cartesian extraction in 2D
"""
_mask = np.ones((self.N, self.N))
_samples = convert_mask_to_locations(_mask)
fourier_op = NonCartesianFFT(samples=_samples, shape=(self.N, self.N))
Img = (np.random.randn(self.num_channel, self.N, self.N) +
1j * np.random.randn(self.num_channel, self.N, self.N))
F_img = np.asarray(
[fourier_op.op(Img[i]) for i in np.arange(self.num_channel)])
Smaps_gridding, SOS_Smaps = get_Smaps(k_space=F_img,
img_shape=(self.N, self.N),
samples=_samples,
thresh=(0.4, 0.4),
mode='gridding',
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
n_cpu=1)
Smaps_NFFT, SOS_Smaps = get_Smaps(k_space=F_img,
img_shape=(self.N, self.N),
thresh=(0.4, 0.4),
samples=_samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
mode='NFFT')
np.testing.assert_allclose(Smaps_gridding, Smaps_NFFT)
def test_stack_3D_error(self):
np.testing.assert_raises(ValueError, get_stacks_fourier,
np.random.randn(12, 3),
(self.N, self.N, self.N))
# Generate random mask along z
sampling_z = np.random.randint(2, size=self.N)
_mask3D = np.zeros((self.N, self.N, self.N))
for idx, acq_z in enumerate(sampling_z):
_mask3D[:, :,
idx] = np.random.randint(2, size=(self.N, self.N)) * acq_z
sampling = convert_mask_to_locations(_mask3D)
np.testing.assert_raises(ValueError, get_stacks_fourier, sampling,
(self.N, self.N, self.N))
def test_sampling_converters(self):
"""Test the adjoint operator for the 2D non-Cartesian Fourier transform
"""
for i in range(self.max_iter):
print("Process test convert mask to samples test '{0}'...", i)
Nx = np.random.randint(8, 512)
Ny = np.random.randint(8, 512)
mask = np.random.randint(2, size=(Nx, Ny))
samples = convert_mask_to_locations(mask)
recovered_mask = convert_locations_to_mask(samples, (Nx, Ny))
self.assertEqual(mask.all(), recovered_mask.all())
mismatch = 0. + (np.mean(np.allclose(mask, recovered_mask)))
print(" mismatch = ", mismatch)
print(" Test convert mask to samples and it's adjoint passes for",
" the 2D cases")
def test_similarity_stack_3D_nfft(self):
"""Test the similarity of stacked implementation of Fourier transform
to that of NFFT
"""
for channel in self.num_channels:
print("Testing with num_channels=" + str(channel))
for N in [16, 32]:
# Nz is the number of slices, this would check both N=Nz
# and N!=Nz
Nz = 16
_mask = np.random.randint(2, size=(N, N))
# Generate random mask along z
sampling_z = np.random.randint(2, size=Nz)
_mask3D = np.zeros((N, N, Nz))
for idx, acq_z in enumerate(sampling_z):
_mask3D[:, :, idx] = _mask * acq_z
_samples = convert_mask_to_locations(_mask3D)
print("Process Stack-3D similarity with NFFT for N=" + str(N))
fourier_op_stack = Stacked3DNFFT(kspace_loc=_samples,
shape=(N, N, Nz),
implementation='cpu',
n_coils=channel)
fourier_op_nfft = NonCartesianFFT(samples=_samples,
shape=(N, N, Nz),
implementation='cpu',
n_coils=channel)
Img = np.random.random((channel, N, N, Nz)) + \
1j * np.random.random((channel, N, N, Nz))
f = np.random.random((channel, _samples.shape[0])) + \
1j * np.random.random((channel, _samples.shape[0]))
start_time = time.time()
stack_f_p = fourier_op_stack.op(Img)
stack_I_p = fourier_op_stack.adj_op(f)
stack_runtime = time.time() - start_time
start_time = time.time()
nfft_f_p = fourier_op_nfft.op(Img)
nfft_I_p = fourier_op_nfft.adj_op(f)
np.testing.assert_allclose(stack_f_p, nfft_f_p, rtol=1e-9)
np.testing.assert_allclose(stack_I_p, nfft_I_p, rtol=1e-9)
nfft_runtime = time.time() - start_time
print("For N=" + str(N) + " Speedup = " +
str(nfft_runtime / stack_runtime))
print("Stacked FFT in 3D adjoint test passes")
def test_check_asserts(self):
# Tests to check for asserts
image, nb_scale, optimizer, recon_type, name = self.test_cases[0]
fourier = NonCartesianFFT(
samples=convert_mask_to_locations(self.mask),
shape=image.shape,
)
kspace_data = fourier.op(image.data)
linear_op, regularizer_op = \
self.get_linear_n_regularization_operator(
wavelet_name=name,
dimension=len(fourier.shape),
nb_scale=2,
gradient_formulation="synthesis",
)
reconstructor = CalibrationlessReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation="synthesis",
verbose=1,
)
np.testing.assert_raises(
ValueError,
reconstructor.reconstruct,
kspace_data=kspace_data,
optimization_alg="test_fail",
num_iterations=self.num_iter,
)
fourier.n_coils = 10
reconstructor = SelfCalibrationReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation="synthesis",
verbose=1,
)
np.testing.assert_raises(
ValueError,
reconstructor.reconstruct,
kspace_data=kspace_data,
optimization_alg=optimizer,
num_iterations=self.num_iter,
)
def test_extract_k_space_center_2D(self):
""" Ensure that the extracted k-space center is right"""
_mask = np.ones((self.N, self.N))
_samples = convert_mask_to_locations(_mask)
Img = (np.random.randn(self.num_channel, self.N, self.N) +
1j * np.random.randn(self.num_channel, self.N, self.N))
Nby2_percent = self.N * self.percent / 2
low = int(self.N / 2 - Nby2_percent)
high = int(self.N / 2 + Nby2_percent + 1)
center_Img = Img[:, low:high, low:high]
thresh = self.percent * 0.5
data_thresholded, samples_thresholded = \
extract_k_space_center_and_locations(
data_values=np.reshape(Img, (self.num_channel,
self.N * self.N)),
samples_locations=_samples,
thr=(thresh, thresh),
img_shape=(self.N, self.N))
np.testing.assert_allclose(center_Img.reshape(data_thresholded.shape),
data_thresholded)
def generate_test_stacked_NFFT(self, shape, field_scale):
""" Factorized code to test 3D-stacked wrapped NFFT with
different homogeneous B0 field shifts at constant time.
"""
for L, i, n_coils in product(self.L, range(self.max_iter),
self.n_coils):
mask = np.random.randint(2, size=shape[:-1])
mask = np.tile(mask[..., None], (1, 1, shape[-1]))
samples = convert_mask_to_locations(mask)
samples = samples[:samples.shape[0] \
- (samples.shape[0] % shape[0])]
field_shift = field_scale * np.random.randint(-150, 150)
field_map = field_shift * np.ones(shape)
# Prepare reference and wrapper operators
fourier_op = Stacked3DNFFT(
kspace_loc=samples,
shape=shape,
implementation='cpu',
n_coils=n_coils,
)
wrapper_op = ORCFFTWrapper(fourier_op, field_map=field_map,
time_vec=np.ones(shape[0]),
mask=np.ones(shape),
num_interpolators=L,
n_bins=self.n_bins)
# Forward operator
img = np.squeeze(np.random.randn(n_coils, *shape) \
+ 1j * np.random.randn(n_coils, *shape))
ksp_fft = fourier_op.op(img)
ksp_wra = wrapper_op.op(img * np.exp(-2j * np.pi * field_shift))
np.testing.assert_allclose(ksp_fft, ksp_wra, rtol=self.rtol)
# Adjoint operator
ksp = np.squeeze(np.random.randn(n_coils, samples.shape[0]) \
+ 1j * np.random.randn(n_coils, samples.shape[0]))
img_fft = fourier_op.adj_op(ksp)
img_wra = wrapper_op.adj_op(ksp * np.exp(2j * np.pi * field_shift))
np.testing.assert_allclose(img_fft, img_wra, rtol=self.rtol)
def test_NFFT_3D(self):
"""Test the adjoint operator for the 3D non-Cartesian Fourier transform
"""
for num_channels in self.num_channels:
print("Testing with num_channels=" + str(num_channels))
for i in range(self.max_iter):
_mask = np.random.randint(2, size=(self.N, self.N, self.N))
_samples = convert_mask_to_locations(_mask)
print("Process NFFT test in 3D '{0}'...", i)
fourier_op = NonCartesianFFT(samples=_samples,
shape=(self.N, self.N, self.N),
n_coils=num_channels,
implementation='cpu')
Img = np.random.randn(num_channels, self.N, self.N, self.N) + \
1j * np.random.randn(num_channels, self.N, self.N, self.N)
f = np.random.randn(num_channels, _samples.shape[0]) + \
1j * np.random.randn(num_channels, _samples.shape[0])
f_p = fourier_op.op(Img)
I_p = fourier_op.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-10)
print(" NFFT in 3D adjoint test passes")
def test_adjoint_stack_3D(self):
"""Test the adjoint operator for the 3D non-Cartesian Fourier transform
"""
for channel in self.num_channels:
print("Testing with num_channels=" + str(channel))
for i in range(self.max_iter):
_mask = np.random.randint(2, size=(self.N, self.N))
_mask3D = np.asarray([_mask for i in np.arange(self.N)])
_samples = convert_mask_to_locations(_mask3D.swapaxes(0, 2))
print("Process Stacked3D-FFT test in 3D '{0}'...", i)
fourier_op = Stacked3DNFFT(kspace_loc=_samples,
shape=(self.N, self.N, self.N),
implementation='cpu',
n_coils=channel)
Img = np.random.random((channel, self.N, self.N, self.N)) + \
1j * np.random.random((channel, self.N, self.N, self.N))
f = np.random.random((channel, _samples.shape[0])) + \
1j * np.random.random((channel, _samples.shape[0]))
f_p = fourier_op.op(Img)
I_p = fourier_op.adj_op(f)
x_d = np.vdot(Img, I_p)
x_ad = np.vdot(f_p, f)
np.testing.assert_allclose(x_d, x_ad, rtol=1e-10)
print("Stacked FFT in 3D adjoint test passes")
def test_sensitivity_extraction_2D(self):
""" This test ensures that the output of the non cartesian kspace
extraction is same a that of mimicked cartesian extraction in 2D
"""
mask = np.ones((self.N, self.N))
samples = convert_mask_to_locations(mask)
fourier_op = NonCartesianFFT(samples=samples, shape=(self.N, self.N))
Img = (np.random.randn(self.num_channel, self.N, self.N) +
1j * np.random.randn(self.num_channel, self.N, self.N))
F_img = np.asarray(
[fourier_op.op(Img[i]) for i in np.arange(self.num_channel)])
Smaps_gridding, SOS_Smaps = get_Smaps(k_space=F_img,
img_shape=(self.N, self.N),
samples=samples,
thresh=(0.4, 0.4),
mode='gridding',
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
n_cpu=1)
Smaps_NFFT_dc, SOS_Smaps_dc = get_Smaps(k_space=F_img,
img_shape=(self.N, self.N),
thresh=(0.4, 0.4),
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
mode='NFFT',
density_comp=np.ones(
samples.shape[0]))
Smaps_NFFT, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=(0.4, 0.4),
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
mode='NFFT',
)
Smaps_hann_NFFT, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun="Hann",
mode='NFFT',
)
Smaps_hann_gridding, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun="Hann",
mode='gridding',
)
Smaps_hamming_NFFT, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun="Hamming",
mode='NFFT',
)
Smaps_hamming_gridding, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun="Hamming",
mode='gridding',
)
Smaps_call_gridding, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun=lambda x: 1,
mode='gridding',
)
Smaps_call_NFFT, SOS_Smaps = get_Smaps(
k_space=F_img,
img_shape=(self.N, self.N),
thresh=0.4,
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun=lambda x: 1,
mode='NFFT',
)
np.testing.assert_allclose(Smaps_gridding, Smaps_NFFT_dc)
np.testing.assert_allclose(Smaps_gridding, Smaps_NFFT)
np.testing.assert_allclose(Smaps_hann_gridding, Smaps_hann_NFFT)
np.testing.assert_allclose(Smaps_hamming_gridding, Smaps_hamming_NFFT)
np.testing.assert_allclose(Smaps_call_gridding, Smaps_call_NFFT)
# Test that we raise assert for bad mode
np.testing.assert_raises(ValueError,
get_Smaps,
k_space=F_img,
img_shape=(self.N, self.N),
thresh=(0.4, 0.4),
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
mode='test')
# Test that we raise assert for bad window
np.testing.assert_raises(
ValueError,
get_Smaps,
k_space=F_img,
img_shape=(self.N, self.N),
thresh=(0.4, 0.4),
samples=samples,
min_samples=(-0.5, -0.5),
max_samples=(0.5, 0.5),
window_fun='test',
mode='gridding',
)
def test_stack3d_self_calibration_recon(self):
# This test carries out a self calibration recon using Stack3D
self.num_channels = 2
self.z_size = 10
for i in range(len(self.test_cases)):
image, nb_scale, optimizer, recon_type, name = self.test_cases[i]
if recon_type == 'cartesian' or name == 24:
continue
# Make a dummy 3D image from 2D
image = np.moveaxis(
np.repeat(image.data[np.newaxis], self.z_size, axis=0), 0, 2)
# Make dummy multichannel image
image = np.repeat(image[np.newaxis], self.num_channels, axis=0)
sampling_z = np.random.randint(2, size=image.shape[3])
sampling_z[self.z_size // 2 - 3:self.z_size // 2 + 3] = 1
Nz = sampling_z.sum()
mask = convert_mask_to_locations(self.mask)
z_locations = np.repeat(convert_mask_to_locations(sampling_z),
mask.shape[0])
z_locations = z_locations[:, np.newaxis]
kspace_loc = np.hstack([np.tile(mask, (Nz, 1)), z_locations])
fourier = Stacked3DNFFT(kspace_loc=kspace_loc,
shape=image.shape[1:],
implementation='cpu',
n_coils=self.num_channels)
kspace_obs = fourier.op(image)
if optimizer == 'condatvu':
formulation = "analysis"
else:
formulation = "synthesis"
linear_op, regularizer_op = \
self.get_linear_n_regularization_operator(
wavelet_name=name,
dimension=len(fourier.shape),
nb_scale=2,
n_coils=2,
n_jobs=2,
gradient_formulation=formulation,
)
# For self calibrating reconstruction the n_coils
# for wavelet operation is 1
linear_op.n_coils = 1
reconstructor = SelfCalibrationReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation=formulation,
num_check_lips=0,
smaps_extraction_mode='Stack',
verbose=1,
)
x_final, _, _, = reconstructor.reconstruct(
kspace_data=kspace_obs,
optimization_alg=optimizer,
num_iterations=5,
)
fourier_0 = FFT(
samples=kspace_loc,
shape=image.shape[1:],
n_coils=self.num_channels,
)
recon = fourier_0.adj_op(fourier_0.op(image))
np.testing.assert_allclose(
np.abs(x_final), np.sqrt(np.sum(np.abs(recon)**2, axis=0)),
0.1)
def test_gridsearch_single_channel(self):
"""Test Gridsearch script in mri.scripts for
single channel reconstruction this is a test of sanity
and not if the reconstruction is right.
"""
image = get_sample_data('2d-mri')
mask = np.ones(image.shape)
kspace_loc = convert_mask_to_locations(mask)
fourier_op = NonCartesianFFT(samples=kspace_loc, shape=image.shape)
kspace_data = fourier_op.op(image.data)
# Define the keyword dictionaries based on convention
metrics = {
'ssim': {
'metric': ssim,
'mapping': {
'x_new': 'test',
'y_new': None
},
'cst_kwargs': {
'ref': image,
'mask': None
},
'early_stopping': True,
},
}
linear_params = {
'init_class': WaveletN,
'kwargs': {
'wavelet_name': 'sym8',
'nb_scale': 4,
}
}
regularizer_params = {
'init_class': SparseThreshold,
'kwargs': {
'linear': Identity(),
'weights': [0, 1e-5],
}
}
optimizer_params = {
# Just following convention
'kwargs': {
'optimization_alg': 'fista',
'num_iterations': 10,
'metrics': metrics,
}
}
# Call the launch grid function and obtain results
raw_results, test_cases, key_names, best_idx = launch_grid(
kspace_data=kspace_data,
fourier_op=fourier_op,
linear_params=linear_params,
regularizer_params=regularizer_params,
optimizer_params=optimizer_params,
reconstructor_kwargs={'gradient_formulation': 'synthesis'},
reconstructor_class=SingleChannelReconstructor,
compare_metric_details={'metric': 'ssim'},
n_jobs=self.n_jobs,
verbose=1,
)
# In this test we dont undersample the kspace so the
# reconstruction is indeed with mu=0, ie best_idx=0
np.testing.assert_equal(best_idx, 0)
np.testing.assert_allclose(
raw_results[best_idx][0],
image,
atol=1e-7,
)
image = get_sample_data('3d-pmri')
image = pysap.Image(data=np.sqrt(np.sum(np.abs(image.data)**2, axis=0)))
# Reducing the size of the volume for faster computation
image.data = image.data[:, :, 48:-48]
# Obtain MRI non-cartesian sampling plane
mask_radial = get_sample_data("mri-radial-samples")
# Tiling the plane on the z-direction
# sampling_z = np.ones(image.shape[2]) # no sampling
sampling_z = np.random.randint(2, size=image.shape[2]) # random sampling
sampling_z[22:42] = 1
Nz = sampling_z.sum() # Number of acquired plane
z_locations = np.repeat(convert_mask_to_locations(sampling_z),
mask_radial.shape[0])
z_locations = z_locations[:, np.newaxis]
kspace_loc = np.hstack([np.tile(mask_radial.data, (Nz, 1)), z_locations])
mask = pysap.Image(data=np.moveaxis(
convert_locations_to_mask(kspace_loc, image.shape), -1, 0))
# View Input
# image.show()
# mask.show()
#############################################################################
# Generate the kspace
# -------------------
#
# From the 2D brain slice and the acquisition mask, we retrospectively
axis=-1)
# View Input
# image.show()
# mask.show()
#############################################################################
# Generate the kspace
# -------------------
#
# From the 3D Orange volume and the acquisition mask, we retrospectively
# undersample the k-space using a cartesian acquisition mask
# We then reconstruct the zero order solution as a baseline
# Get the locations of the kspace samples
kspace_loc = convert_mask_to_locations(mask.data)
# Generate the subsampled kspace
fourier_op = FFT(samples=kspace_loc, shape=image.shape)
kspace_data = fourier_op.op(image)
# Zero order solution
image_rec0 = pysap.Image(data=fourier_op.adj_op(kspace_data),
metadata=image.metadata)
# image_rec0.show()
# Calculate SSIM
base_ssim = ssim(image_rec0, image)
print(base_ssim)
#############################################################################
# FISTA optimization
def test_online_accumulating_calibrationless(self):
self.num_channels = 2
for i in range(len(self.test_cases)):
image, nb_scale, optimizer, recon_type, name = self.test_cases[i]
if recon_type != 'cartesian':
continue
if optimizer == 'condatvu':
formulation = "analysis"
else:
formulation = "synthesis"
image_multichannel = np.repeat(image.data[np.newaxis],
self.num_channels,
axis=0)
fourier = FFT(samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels)
kspace_data = fourier.op(image_multichannel)
linear_op, _ = \
self.get_linear_n_regularization_operator(
wavelet_name=name,
dimension=len(fourier.shape),
nb_scale=2,
n_coils=2,
n_jobs=2,
image_shape=image.shape,
)
regularizer_op_gl = GroupLASSO(weights=0)
linear_op.op(image_multichannel)
regularizer_op_owl = OWL(
alpha=0,
beta=0,
mode='band_based',
n_coils=self.num_channels,
bands_shape=linear_op.coeffs_shape,
)
for regularizer_op in [regularizer_op_gl, regularizer_op_owl]:
print(image, nb_scale, optimizer, recon_type, name,
regularizer_op)
kspace_gen = KspaceGeneratorBase(full_kspace=kspace_data,
mask=fourier.mask,
max_iter=10)
reconstructor = CalibrationlessReconstructor(
fourier_op=fourier,
linear_op=linear_op,
regularizer_op=regularizer_op,
gradient_formulation=formulation,
num_check_lips=0,
verbose=1,
)
x_final, costs, _ = reconstructor.reconstruct(
kspace_data=kspace_gen,
optimization_alg=optimizer,
)
fourier_0 = FFT(
samples=convert_mask_to_locations(self.mask),
shape=image.shape,
n_coils=self.num_channels,
)
data_0 = fourier_0.op(image_multichannel)
# mu is 0 for above single channel reconstruction and
# hence we expect the result to be the inverse fourier
# transform
np.testing.assert_allclose(x_final, fourier_0.adj_op(data_0),
0.01)